1. RCO2 Redes Locais (LANs): Arquitetura IEEE 802
Lecture slides prepared by Dr Lawrie Brown for “Data and Computer Communications”, 8/e, by William Stallings, Chapter 15 “Local Area Network Overview”.

2. Arquitetura IEEE 802
Conjunto de padrões no escopo das camadas de enlace e física
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

3. Arquitetura IEEE 802
Exemplos de padrões partes da arquitetura IEEE 802:
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

4. Arquitetura IEEE 802 Alguns padrões da família IEEE 802: 802.2 – LLC
802.3 – Equivalente ao Ethernet 10 Mbps
802.3u – Fast Ethernet
802.3z – Gigabit Ethernet
802.1 – Interconexão e gerenciamento de LANs e MANs
802.1q – VLAN tagging
802.1p – Priorização de tráfego
802.1d – Interconexão de LANs e Spanning Tree
802.1x – Controle de acesso baseado em porta
Mais em
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

5. Arquitetura IEEE 802 Camada Física (PHY): Codificação
Geração de preâmbulo (para sincronização)
Transmissão e recepção de bits
Meio físico e topologia
Camada de Enlace:
Subcamada de acesso ao meio (MAC)
Especificação do formato de quadro
Endereçamento
Controle de acesso ao meio (MAC)
Subcamada LLC
Controle de erro e fluxo (na prática não usados)
Interface para camadas superiores
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

6. Arquitetura IEEE 802 LLC: Link Layer Control
Protocolo de enlace baseado no HDLC
Serviços:
Não-conectado e não-confirmado: sem garantia de entrega de quadros
Conectado: implica controle de erros e de fluxo, com estabelecimento prévio do enlace
Não-conectado e confirmado: não necessita de estabelecimento prévio de enlace
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

7. Arquitetura IEEE 802 Quadro MAC com PDU LLC:
Mas LLC na prática não é usado ! Em LANs cabeadas, o quadro MAC assim se resume ao quadro Ethernet:
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
ou “Ether Type”

8. Arquitetura IEEE 802
Exemplo de quadro e PDUs de protocolos de camadas superiores
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

9. Arquitetura IEEE 802 IEEE 802.3 e variações (ou “Ethernet”):
Padrões para LANs cabeadas
Ethernet: nome de uma rede concebida na Xerox por Robert Metcalfe e outros entre 1973 e 1975
Metcalfe pensou em uma rede capaz de conectar centenas de equipamentos a altas velocidades, tipicamente dentro de um edifício.
Transformada em padrão em 1980 por DEC, Xerox e Intel, junto com a IEEE
Competia então com Token Ring e Token Bus
Após discussões e aperfeiçoamentos, tornou-se base para o padrão IEEE em 1982
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

10. Arquitetura IEEE 802 IEEE 802.3 e variações (ou “Ethernet”):
Diagrama originalmente feito por Metcalfe em 1976, para apresentar a Ethernet em uma conferência
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

11. Arquitetura IEEE 802 IEEE 802.3 e variações (ou “Ethernet”):
Transmissão simplificada em uma rede Ethernet
Usa-se endereçamento:
Quadros contêm endereços de origem e destino
Todas estações recebem o quadro
Apenas destinatário o copia e repassa para camada superior
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

12. Arquitetura IEEE 802 IEEE 802.3 e variações (ou “Ethernet”):
Três gerações de redes Ethernet:
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

13. Arquitetura IEEE 802 IEEE 802.3 (Ethernet):
Originalmente uma rede a 10 Mbps e meio compartilhado (topologia em barramento)
Codificação usada: Manchester
Meios físicos:
10base5: Cabo coaxial grosso (500 m)
10base2: Cabo coaxial fino (185 m)
10baseT: Par-trançado (100 m,topologia estrela)
10baseFL: Fibra ótica (2km, topologia estrela)
Alcances máximos extensíveis com repetidores ou hubs
Máximo de 4 repetidores
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

14. Arquitetura IEEE 802 IEEE 802.3 (Ethernet): camada PHY
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

15. Arquitetura IEEE 802 IEEE 802.3 (Ethernet):
Placa de rede e cabo para 10base2:
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Cabo coaxial fino com conector BNC
Uma placa de rede (NIC) com conector BNC, para 10base2

16. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações:
Domínio de colisão: conjunto de estações cujas transmissões são capazes de colidirem entre si.
Pode ser dividido em segmentos com o uso de bridges (pontes) ou switches
Cada segmento é um novo domínio de colisão

17. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações:
Domínio de broadcast: conjunto de estações que recebem respectivos quadros enviados em broadcast.
Bridges e switches repetem esses quadros por todos os segmentos
Domínios de colisão na figura b) também formam um domínio de broadcast

18. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações: Ethernet comutada (switched Ethernet)
Cada estação forma um domínio de colisão separado
A banda é dividida entre switch e estação, e não mais entre as N estações

19. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações: Ethernet comutada (switched Ethernet)
Comparação entre uso de hub e de switch
Uso de hub
Uso de switch

20. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações: Ethernet full-duplex
Em Ethernet comutada, torna-se possível operação em full-duplex
Estações podem então receber e transmitir ao mesmo tempo (precisam no entanto de dois links)

21. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE e variações: Ethernet full-duplex
Em modo full-duplex, o CSMA/CD torna-se desnecessário !
Para cada estação, o meio para envio é dedicado (sem risco de colisão, portanto).
Assim, não é mais necessário ouvir a portadora, ou detectar colisões ...

22. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
Proposto em 1995
Mantém MAC para compatibilidade com 802.3
Agrega capacidade de auto-negociação
Negocia automaticamente taxa de transmissão e modo duplex
Torna-se capaz portanto de operar a 10 Mbps ou 100 Mbps, half ou full-duplex
Inclui modificações nos componentes físicos (PHY)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

23. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
Camada PHY:
RS: Subcamada de Reconciliação
Passagem de dados a 4 bits para a MII
MII:
Opera a 10 ou 100Mbps
Comunicação a 4 bits entre PHY e RS
Funções de gerenciamento
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

24. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
Meios físicos:
100baseTX: Par-trançado dois pares (codificação 4B5B e MLT-3), alcance de 100 m
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

25. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
11101 F
11100 E
11011 D …
10100 2
01001 1
11110
4B5B
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
MLT-3: bit como presença ou ausência de transição
MLT-3 alterna de -1 a 0 a +1, volta a 0, depois para -1, prosseguindo indefinidamente
Um zero é codificado como uma interrupção nessa progressão.

26. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet): Rede a 100 Mbps
Meios físicos:
100baseT4: Par-trançado 4 pares (codificação 8B6T), alcance de 100 m
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

27. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet):
Meios físicos (cont.):
100baseFX: Fibra ótica (codificação 4B5B e NRZI), alcance de 400 m.
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

28. Arquitetura IEEE 802 IEEE 802.3u (Fast Ethernet):
Meios físicos (cont.):
100baseSX: Fibra ótica (menor custo, menor distância), alcance de 300 m.
100baseBX: Fibra ótica (uma fibra com divisão por frequência para RX e TX), alcance de 10,20 ou 40 km.
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

29. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
Auto-negociação: baseada em FLP (Fast Link Pulses)
Pulsos enviados por dispositivos quando não recebem ou transmitem dados
Sequências de até 33 pulsos unipolares, positivos, com duração de 100 ns cada

30. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE 802.3u (Fast Ethernet): rede a 100 Mbps
Há 17 pulsos separados por 125 µs (tolerância de 14 µs)
Entre cada par de pulsos pode ou não existir um outro pulso
Presença de pulso intermediário = bit 1
Ausência de pulso intermediário = bit 0
Assim, cada FPS contém uma palavra de 16 bits (LCW – Link Code Word)

31. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE 802.3u (Fast Ethernet):
LCW - Link Code Word:

32. Arquitetura IEEE 802 IEEE 802.3z (Gigabit Ethernet): Rede a 1 Gbps
Proposto em 1998.
Meios físicos:
1000baseT: Par-trançado 4 pares, codificação TCM-4, alcance de 100m.
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

33. Arquitetura IEEE 802 IEEE 802.3z (Gigabit Ethernet): Rede a 1 Gbps
Meios físicos:
1000baseLX: Fibra ótica, alcance de 5 km.
1000baseSX: Fibra ótica (menor custo, menor distância), alcance de 550 m.
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

34. We turn now to a discussion of local area networks (LANs)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Arquitetura IEEE 802
IEEE 802.3aX (10 Gigabit Ethernet): Rede a 10 Gbps
Padrões propostos a partir de 2002
Operação somente em modo full-duplex e com switches
Acesso ao meio prescinde de CSMA/CD !
Múltiplos PHY, porém ainda não está claro quais terão maior aceitação ...

35. Arquitetura IEEE 802
IEEE 802.3aX (10 Gigabit Ethernet): Rede a 10 Gbps
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Múltiplos
PHY

36. Arquitetura IEEE 802
IEEE 802.3aX (10 Gigabit Ethernet): Rede a 10 Gbps
Codificação usada (10GbaseT): PAM-16
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Comparação entre níveis de tensão para MLT-3 (100baseT), PAM-5 (1000baseT) e PAM-16 (10GbaseT)

37. Arquitetura IEEE 802
IEEE 802.3aX (10 Gigabit Ethernet): Rede a 10 Gbps
Switch e NIC
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

38. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
MAC é o mesmo para diferentes gerações (802.3, 802.3u, 802.3z)
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Visão funcional da subcamada MAC contida na norma IEEE 802.3

39. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Tabela de parâmetros
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

40. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Fluxograma para transmissão de quadro
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

41. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Exemplo de ocorrência de colisão
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Ao detectarem a colisão, as estações envolvidas aplicam um procedimento de resolução de conflito

42. Arquitetura IEEE 802
Meio ocioso por
9.6 us ... inicia transmissão
Colisão
detectada
Meio ocioso...
inicia transmissão
Jam com 32 bits 1
colisão
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
Jam com 32 bits 1

43. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Quando colisão é detectada, as estações envolvidas:
Enviam um sinal de jam por 32 tempos de bit
Incrementam o contador de tentativas de transmissão
Sorteiam um tempo de espera dado por:
0≤𝑟< 2 𝑘 𝑘=𝑚𝑖𝑛 𝑛,10 𝑟∈ℕ
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.
r: tempo de espera (quantidade de tempos de slot)
n: contador de tentativas de transmissão de um mesmo quadro (máximo: 16 tentativas)

44. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Lembrando que tempo de slot é duas vezes o tempo para sinal percorrer todo o meio de transmissão (no pior caso)
No padrão IEEE 802.3, tempo de slot = 9.6 µs
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

45. Arquitetura IEEE 802 IEEE 802.3 e variações: subcamada MAC CSMA/CD
Fluxograma para recepção de quadro
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.

46. Arquitetura IEEE 802 Referências: Padrão IEEE 802.3 seções 1 a 5
(ver
Andrew Tanenbaum. Redes de Computadores 3a ed. Capítulo 4
We turn now to a discussion of local area networks (LANs). The variety of applications for LANs is wide. To provide some insight into the types of requirements that LANs are intended to meet, this section provides a brief discussion of some of the most important general application areas for these networks.
A common LAN configuration is one that supports personal computers. LANs for the support of personal computers and workstations have become nearly universal in organizations of all sizes. Even those sites that still depend heavily on the mainframe have transferred much of the processing load to networks of personal computers. Perhaps the prime example of the way in which personal computers are being used is to implement client/server applications. For personal computer networks, a key requirement is low cost. In particular, the cost of attachment to the network must be significantly less than the cost of the attached device. Thus, for the ordinary personal computer, an attachment cost in the hundreds of dollars is desirable. For more expensive, high-performance workstations, higher attachment costs can be tolerated.
Backend networks are used to interconnect large systems such as mainframes, supercomputers, and mass storage devices. The key requirement here is for bulk data transfer among a limited number of devices in a small area. High reliability is generally also a requirement. Typical characteristics include: High data rates, High-speed interface, Distributed access, Limited distance, and Limited number of devices.